A Comprehensive Guide to Sending and Testing WebSockets with Postman

Real-time, bi-directional communication has become indispensable in many modern web applications. WebSocket technology is at the forefront of this transformation, offering a persistent connection that eliminates the need for continuous HTTP polling. This blog will walk you through the steps to establish and test WebSocket connections using Postman.

What is WebSocket and How Does it Work?

WebSocket is an advanced protocol that supports real-time, bidirectional communication between clients and servers through a single, persistent connection. Unlike traditional HTTP, which operates on a request-response model, WebSocket allows for continuous data flow without the need for repeated requests. This makes it ideal for applications requiring instant updates, such as chat applications, online gaming platforms, and live sports tickers.

The process begins with a simple HTTP handshake initiated by the client, requesting an upgrade to the WebSocket protocol. Once the server agrees, the interaction shifts to a full-duplex WebSocket connection, facilitating real-time data exchange.

WebSockets in Postman

Recognizing the importance of real-time communication, Postman has integrated WebSocket support into its toolbox. This integration lets developers create, send, and analyze WebSocket requests in the same environment they use for REST, SOAP, and GraphQL testing.

Here’s a concise, step-by-step guide to using WebSockets in Postman.

Tutorial: How to Send and Test WebSocket Connections with Postman

Step 1: Open Postman

Launch the Postman application. If you haven’t installed it yet, download it from the official website. Make sure you’re using version 8.5.0 or later.

Step 2: Create a New Request

Click the “New” button in the top left corner of the Postman interface to create a new request.

Step 3: Select WebSocket Request

From the dropdown menu, select “WebSocket Request.” A new tab will open specifically for WebSocket requests.

Step 4: Enter WebSocket Server URL

In the new tab, you’ll see a request URL field. Enter the URL of your WebSocket server, typically starting with “ws://” for unsecured connections or “wss://” for secure connections.

Step 5: Set Request Headers (Optional)

If your WebSocket server requires specific headers, add them in the Headers tab. WebSocket handshake requests can include headers just like HTTP requests.

Step 6: Connect to the WebSocket Test Server

Click the “Connect” button on the far right of the request URL field. This initiates the WebSocket handshake. Postman will handle the protocol upgrade automatically.

Step 7: Check WebSocket Connection

Once connected, the status next to the “Connect” button will change to “Connected.” You’ll also see a log of the connection status in the console at the bottom.

Step 8: Send Messages to the WebSocket Server

Now you can send messages. Enter your message in the text box at the bottom of the interface. These messages can be in JSON, XML, or any other text format your server accepts.

Step 9: View Server Messages

Messages received from the server will be displayed above the input field, allowing you to monitor real-time data exchanges.

Step 10: Disconnect

After completing your tests, click the “Disconnect” button to close the WebSocket connection.

Troubleshooting with Apidog

If you encounter issues with Postman while testing WebSockets, consider using an alternative tool like Apidog. Apidog offers a user-friendly interface for creating, sending, and testing WebSocket requests. It’s available as a web application, a desktop app for Windows, macOS, and Linux, or a CLI tool for continuous integration.

Related reading: [SOLVED] WebSocket Connection Failed

Postman Alternative: Apidog

Apidog is a robust, cloud-based API platform designed to simplify API testing, debugging and development. It offers a range of features that make it an excellent alternative to Postman:

• Enhanced WebSocket Support: Allows for parameter handling, saving requests, and sending binary messages in Base64 or hex format.
• Automation and Customization: Robust automation testing capabilities and extensive customization options.
• User Interface: Intuitive, visually appealing, and designed for ease of use.
• Team Collaboration: Features for team management, sharing tests, and collaborative documentation.
• Online Document Sharing and Mocking Data: Supports online document sharing and automatic mocking of human-friendly data.

Establishing a WebSocket Connection in Apidog

1. Click the “+” button on the left sidebar and select “New WebSocket API”.

2. Enter the WebSocket API URL to establish a connection.

3. Draft messages under the Message tab in various text formats or binary messages using Base64 or hexadecimal.

4. View message: The Messages below show the connection status, sent messages, and received messages in chronological order.

Apidog vs. Postman: WebSocket Handling Comparison

While both Apidog and Postman offer extensive API testing features, Apidog provides a user-friendly platform with greater flexibility and comprehensive WebSocket support.

Conclusion

Postman is a powerful tool for API testing, and its WebSocket support adds another dimension to its capabilities. However, if you find Postman’s limitations restrictive, especially for WebSocket testing, consider Apidog as a robust alternative that offers more flexibility and a better user experience.

Whether you’re a seasoned developer or a newcomer, enhancing your productivity and efficiency is crucial, and the right tools can make all the difference. Happy testing!